integra wet radio

Hi everyone. I've got an issue, and the only solution really doesn't make any sense to me. I've got a 95 Integra. I've also got an Excelon that Kenwood voided the warranty on claiming that it's been wet. Upon it's return, I opened it(why not, no warranty anyway). Sure enough, it had one little white crusty spot that looked like moisture corrosion. This thing isn't a year old, and it went from the Kenwood box into my dash, where it has stayed since. My car hasn't had a busted windshield. I had another Excelon before this that lived in the same spot for almost 2 years with no issues. I don't get it.

What happened was this. We'd gone on a trip. It was HOT outside and humid, so that A/C blasted all day. After driving for around 3 hours, my head unit shut off. No noises, no anything, just off. I figured I'd mess with it at home. Upon inspection, I found no signs of anything wrong. Fuses were good, and the eject light illuminated. So, I had it sent in for warranty. See above results. I don't run my sunroof open, so it's not from that. The car hasn't been wrecked. Nothing has changed.

I'm left thinking that the only thing it could have been was condensation from the big, black housing that all the A/C ducting comes off of. It is right behind the radio, and it does get COLD. Could the heat of the radio, the humidity on a 98* day, and that cold ducting have condensated enough to short out my radio?

Thanks in advance everyone. I'm terrified to put another head unit in until I figure out what happened.

To be as specific as possible:
95 Acura Integra coupe
Kenwood Excelon KDC-X994
I didn't use a kit to install it. I attached the sleeve to a Honda pocket for a cleaner look.

Stranger things have happened...

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To master and control electricity is perfection. *evil laugh*

yes its completely possible. just like if you put a cold drink on top of the radio for a little while, the condensation will eventually make its wak to the circuit board. same problem that people have with flip out tvs that block the ac vent, it will eventually short out the screen. wrap the exposed ducts in some kind of foam insulation just like one of those foam drink holders and it shouldnt happen again

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I usually place a plastic bag or similar over the radio etc to deflect any water. But I have body & screen leak problems - no air-con.
But any insulation over cold pipes may eventually cool too - it depends on heat (rate) from ambient versus "cold rate" to the skin (ie, heat rate from surface to the cold ducts).

Just don't block any cooling vents on the radio etc, though heatsinks should not not require covering (since they are usually sealed).